1. Field of the Invention
The present invention relates to a non-slip structure that provides a metal plate with a non-slip protruded piece, which is highly effective in preventing a slip without any trouble caused by a through hole, thereby enhancing reliability.
2. Description of the Related Art
As non-slip structures of a metal plate which constitute floors, aisles, stairs, or decorative laminated sheets and the like of building structures, or floors and steps of buses, trucks, special vehicles and the like and, furthermore, top sides and decks of railway rolling stocks, marine vessels and the like in addition to temporary sole plates and the like of civil works and the like, heretofore, the technologies such as enumerated below have been known.
(1) A banded steel plate 11 is known, which has a non-slip banded pattern rounded and formed when a steel plate is flat-rolled (see FIG. 4(A)).
Since the height of the banded pattern 13, formed when the steel plate is flat-rolled, is low and also has a curved shape, a non-slip effect can be expected as long as it is used for a relatively good working condition. Even in such a case, not much non-slip effect can be expected (see FIGS. 4 (B) and 4(C)).
(2) A non-slip structure is known, which is laminated with a non-slip sheet comprising a sandpaper because the upper cover of construction equipment is taken as a tread.
However, this non-slip sheet is not expected to bring out satisfactory effect since the grain is crushed promptly, depending on its use.
(3) Hence, in order to eliminate these troubles, a structure is known, in which a through hole 22 having a round shape or star-like shape is first formed by punching in a steel plate 21 and, then, a large number of patterns 23 that are made by pulling up the peripheral hem of the through hole 22 by a press and the like are arranged (see FIG. 5).
In this non-slip steel plate 21, since the height of the pulled up portion of the pattern 23 can be sufficiently secured, which also becomes a sharply chopped off surface 27 by punching, much stronger non-slip effect can be expected.
Consequently, this non-slip steel plate 21 is used particularly at elevated working floors, and locations in which the non-slip effect is spoiled due to rainwater and slurries, and the like.
However, since the above-described non-slip steel plate is cut with the through hole, depending on its application, it is inevitable that there arise problems such as rainwater and slurries falling down below the tread, or fiery winds and a diffusion of noises inversely rolling up from below to the tread or the like.
Hence, this non-slip steel plate is integrally welded on a separate floor surface made of a flat steel plate or firmly fixed to it by bolting as necessary.
Since bolting makes it possible to separate the non-slip steel plate and the flat steel plate, which becomes the floor surface, it is possible to prevent a rusty fluid from arising out of rainwater accumulated between the non-slip steel plate and the flat steel plate or to clean up dusts accumulated in each non-slip pattern.
Nevertheless, in either case, since the floor structure is twofold, it leads to a rise in the manufacturing cost because of the twofold structure.
The present invention has been made in view of the above-described circumstances, and the main object of the invention is to provide a highly reliable non-slip structure, which is highly effective in preventing a slip without any trouble caused by the through hole.
A further object of the invention is to provide a non-slip structure, which is good in draining.